Centering device



J IRVI-NG GENTERING DEVICE. No. 352,693. Patented Nov. 16, 1886.

- WITNESSES: [a j NVENTOR:

' BY W I I ATTORNEYS.

N. PETERS, PhMo-L'nhcgmphun Wnhingiom n. c.

, nN-ITED S AT PATENT ()r-rrcn.

Jonn'ravme, OF WARREN, MASSACHUSETTS.

CENTERING DEVICE.

SPECIFICATION forming part of Letters Patent No. 352,693, dated November 16. 1886. Application filed February 26,1886. Serial No. l93.338. (No model.)

To all whom it may concern:

Be it known that 1, JOHN IRVING, of Warren, in thecounty of-Worcester and State of Massachusetts, haveinvented a new and Improved Centering Device, of which-thefollowing is a full, clear, and exact description.

The objectof my invention is to provide. a new and improved device for centering rods, shafts, cylinders, &c.", and for laying out equidistant centers for holes in a circle at a given radius from the center. I

The invention consists of a frame provided with two movable external and internal calipering heads, each attached to a rack which is in gear with a central pinion of an index and ot a graduated radius-bar.

The invention also consists of various parts and details and combinations of the same, hereinafter more fully set forth,and-pointed outin the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification,

' in which similar letters ofreference indicate corresponding parts in all the figures.

Figure 1 isa plan view of my improvements,

parts being broken out and others in section- Fig. 2 is a longitudinal vertical section of the same on the line as 00 in Fig. 1. Fig. 3 is a vertical cross-section of the same on the line y y of Fig. 1. Fig. 4: is a plan view of the same, with index and graduated radius-bar attached for laying out equidistant centers in a circle; andFig. 5 is a vertical cross section of the same on the line 2: z of Fig. 4.

The main frame A of the centering device consists of the bottom plate, A, having the end pieces, A and A and the side pieces,'A

and A ,which form the recesses A and Aland of the top plate,A ,secured at the end pieces, A and A to the bottom plate, A, In the center of the frame A is secured the pin B,

having a central aperture, B, and on the pin B is placed and turning loosely on the same, the pinion O, which meshes on its sides with the racks D and D, sliding between the top plate, A ,and the bottom plate, A,and resting partly against the side pieces, A and A To one outer end of each of the racks D and D is secured a calipering head, E, in such a manner that they are in opposite directions from the central pin,B, and equidistant from the center of the same. The calipering heads E are recessed and fit over and slide on the frame A. The bottom parts, E, of the calipering heads Eareprovided on each side with beveled edges E, which form the external and internal calipering edges of the devices. The upper parts, E ,'of the calipering'heads E are each provided with a short handle, E",by which-the calipering head may be easily moved on the frame A. They also act as calipers for small holes. To the side part, E of each calipering head, which is secured'to ruck D or D, is fastened a short'arm, F, having a recess, F, in which slides a bar, F,

and provided on its outer end with a knob,F The. side parts, E ot'the calipering-heads E and theshort arms E slide in the recesses A and A, formed by the side pieces, A and A of the frame A. Attached to the bottom plate,

pinion G, are the lugs G and G, to each of whichand to the end pieces, A andA of the frame A are secured, respectively, the rods H I spring H.

a cylinder, for instance. is obtained by sliding the calipering heads E E on the frame A so that the distance between the outer edges of after which the bars F are pressed inwardly until their recessed inner ends fit over the rods H'H. The calipering heads are then moved inwardly toward each other until the outer edges of the bottom parts, E, rest against the inner face of the cylinder, as shown in Figs. 1 and 2. The springs H are compressed by the means of the bar F, and exert now an outward pressure against the said calipers and hold the same in place on theinner face of the cylinder. It will also be seen that when one calipering head E is moved to or from the pin B the other distance to or from the pin B. A small plug, I, having a central recess, 1', on the top, is placed in the aperture B of the pin B. The recess 1 is then exactly in the center of the cylinder to be centered, and forms a resting point for the-legof the compass with which the operator performs'the Work required.

, For centering rods or shafts the inner edges having a semicircular recess on its inner end A, and placed on the opposite sides of the- H, around each of which isplaced the coiled" inward motion of the cal-ipering heads E by I calipering head is caused to slide thesame.

This de\ ice is used as follows: The center of '80 the bottom parts, E, is a trifle larger than the inside diameter of the cylinder to be centered,

ture B of the pin B, the point of the said een ter-plug J being the center of the rod or shaft to be operated on. A slight tap with a hammer on top of the center-plug J leaves a center dent on the rod or shaft, the pin acting as guide during the operation.

For laying out equidistant centers for holes in a circle, I employ an index, K, having the usual arrangement of dents, K,or apertures on the top plate, K". To the latter is attached on its bottom a graduated radius-bar, L, on which slides the center-plug holder M, which can be securely held at any desired point 011' the radius-bar L by the setserew M. The plug-holder M is provided with an offset, M, having a vertical aperture in which the centering-plug J is inserted for marking the given number of centers in a circl The index K swings loosely on a recessed shank, N, provided on its lower end with a screw-threaded pin, N, which is placed in the aperture B of the pin Band securely held to the frame A by the nut N. On the upper end of the shank N is formed a collar, N from which projects a screw-threaded pin, N, upward, on which is placed the arm 0, having a slot, 0, and a setscrew, 0"", and can be secured on the pin N and the collar N by the nut N This device is used as follows: The frame A is placed across the work to be operated on and the calipering head E adjusted against the inner or outer edges of the work, as before described, whereby the center of the object is obtained in the center of the pin B. The index K and its radius-bar L are placed on the frame A by inserting the pin N into the aperture B of the pin 'B and fastening the shank N to the frame A by tightening the nut N", as shown in Fig. 5. The plug-holder is then moved to a point on the graduated radius-barL which is to be the radius of the circle in which the centers are to be marked. The arm 0 is then moved on the pin N until the point of the set-screw O" is in line with the circle of the respective dents K on the index-plate K, which are to be marked, and the arm 0 is then fastened to the collar N by the nut N Theindex-plateK andits radius-barLare then turned until a dent is under the point of the set-screw O, which is then screwed down into the respective dent K, whereby the indexplate K and its radius-bar L are held in place. The center-plug J is then inserted into the aperture M on the plug-holder M, and the first center is then marked. The set-serew O is then screwed upward to set the index-plate K free, which is then turned until the next dent K comes under the point of the set-screw O, which is screwed downward to fasten the index-plate K again to the arm 0, and the above-described operation is repeated until all the centers on the work are marked.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent- 1. In a centering device, the combination of a frame with internal and external calipering heads attached to racks which mesh into a pinion turning on a central hollow pin, with stationary rods attached to the frame, with springs placed on the said rods, and with sliding bars fitted to the calipers tocompress the said springs, substantially as shown and described.

2. In a centering device, a frame on which slide internal and external calipering heads attached to racks which mesh into a pinion turning on a hollow pin, and provided with stationary rods around which are placed springs which are compressed by sliding bars, in combination with an index and graduated radiusbar turning on a shank provided with an arm and set-screw, the said shank being secured in the center of the frame, substantially as shown and described.

3. In a centering device, the frame A, the

pin B, having an aperture, B. the pinion O,

the rods H, and the springs H, in combination with the racks D and D, and the calipering heads, substantially as shown and described.

4. In a centering device, the frame A, the pin B, the pinion C, the rods H, and the spring H, in comblnation with the racks D and D, the calipering heads E, having the beveled inner and outer edges, E and the sliding bar F, substantially as shown and described.

5. In a centering device, the frame A, the pin B, having the aperture B, the pinion (l, the racks D and D, the calipering heads E E, the rods H H, and the springs H, in combination with the index K, provided with a graduated radius-bar, the shank N, and the adj ustable arm 0, substantially as shown and described.

6. In a centering device, the pinion O, the racks D and D, the calipering heads E, provided with the beveled edges E the short arm F, and the sliding bar F in combination with the rods H, secured in the frame A, and the springs H, substantially as shown and described.

7. In a centering device," the frame, the pin B, the pinion O, the racks D and D, the calipering heads E, the rods H, the springs H,

the shank N, and the adjustable arm 0, pro-' vided with the set-screw O in combination with the index-plate K the graduated radius.- bar L, and the center-plug holder M, substantially as shown and described.

JOHN IRVING.

Witnesses:

J. HENRY ADAMS, W. E. J ONES.

Ils 

